The present invention relates generally to medical devices, systems and methods, and more particularly to small, low cost, portable infusion devices and methods that are useable to achieve precise, sophisticated, and programmable flow patterns for the delivery of therapeutic liquids to a mammalian patient.
Today, there are numerous diseases and other physical ailments that are treated by various medicines including pharmaceuticals, nutritional formulas, biologically derived or active agents, hormonal and gene based material and other substances in both solid or liquid form. In the delivery of these medicines, it is often desirable to bypass the digestive system of a mammalian patient to avoid degradation of the active ingredients caused by the catalytic enzymes in the digestive tract and liver. Delivery of a medicine other than by way of the intestines is known as parenteral delivery. Parenteral delivery of various drugs in liquid form is often desired to enhance the effect of the substance being delivered, insuring that the unaltered medicine reaches its intended site at a significant concentration. Also, undesired side effects associated with other routes of delivery, such as systemic toxicity, can potentially be avoided.
Often, a medicine may only be available in a liquid form, or the liquid version may have desirable characteristics that cannot be achieved with solid or pill form. Delivery of liquid medicines may best be accomplished by infusing directly into the cardiovascular system via veins or arteries, into the subcutaneous tissue or directly into organs, tumors, cavities, bones or other site specific locations within the body.
Parenteral delivery of liquid medicines into the body is often accomplished by administering bolus injections using a needle and syringe, or continuously by gravity driven dispensers or transdermal patch technologies. Bolus injections often imperfectly match the clinical needs of the patient, and usually require larger individual doses than are desired at the specific time they are given. Continuous delivery of medicine through gravity feed systems compromise the patient""s mobility and lifestyle, and limit the therapy to simplistic flow rates and profiles. Transdermal patches have special requirements of the medicine being delivered, particularly as it relates to the molecular structure, and similar to gravity feed systems, the control of the drug administration is severely limited.
Ambulatory infusion pumps have been developed for delivering liquid medicaments to a patient. These infusion devices have the ability to offer sophisticated fluid delivery profiles accomplishing bolus requirements, continuous infusion and variable flow rate delivery. These infusion capabilities usually result in better efficacy of the drug and therapy and less toxicity to the patient""s system. An example of a use of an ambulatory infusion pump is for the delivery of insulin for the treatment of diabetes mellitus. These pumps can deliver insulin on a continuous basal basis as well as a bolus basis as is disclosed in U.S. Pat. No. 4,498,843 to Schneider et al.
The ambulatory pumps often work with a reservoir to contain the liquid medicine, such as a cartridge or syringe, and use electro-mechanical pumping or metering technology to deliver the medication to the patient via tubing from the infusion device to a needle that is inserted transcutaneously, or through the skin of the patient. The devices allow control and programming via electromechanical buttons or switches located on the housing of the device, and accessed by the patient or clinician. The devices include visual feedback via text or graphic screens, such as liquid crystal displays known as LCD""s, and may include alert or warning lights and audio or vibration signals and alarms. The device can be worn in a harness or pocket or strapped to the body of the patient.
Currently available ambulatory infusion devices are expensive, difficult to program and prepare for infusion, and tend to be bulky, heavy and very fragile. Filling of these devices or their reservoirs can be difficult and require the patient to carry both the intended medication as well as filling accessories when traveling or even just going to work. The accuracy and safety requirements of these devices are extremely important, based both on the medicine being delivered and the condition of the patient. Therefore, the devices require specialized care, maintenance and cleaning to assure proper functionality and safety for their intended long term use. The devices are usually sold for $4,000 to $6,000 requiring maintenance of the device for four or more years to justify the expenditure. Also due to the cost, replacement devices are not easily available or practical. Any damage to the device, such as that caused by it being dropped, result not only in the costs of repair or replacement, but also in a period of discontinued therapy. The high cost of the device is a concern of healthcare providers who approve and prescribe the use of the device, limiting the expansion of the patient populations and therapies for which the devices can be used.
Clearly, therefore, there is a need for a programmable and adjustable infusion system that is precise and reliable and can offer clinicians and patients a small, low cost, light weight, simple to use alternative for parenteral delivery of liquid medicines.
The applicant has determined that a sophisticated ambulatory infusion device that can be programmed to reliably deliver variable flow profiles of liquid medications, yet is small, light weight and low cost, is needed. Smaller and lighter devices are easier to carry and are more comfortable for the patient, even allowing the device to be adhesively attached to the patient""s skin similar to a transdermal patch. An inexpensive device allows greater flexibility in prescribing the device for use by reducing the financial burden on healthcare insurance providers, hospitals and patient care centers, as well as patients themselves. In addition, low cost devices make more practical the maintenance of one or more replacement devices. If the primary device is lost or becomes dysfunctional, availability of the replacement avoids costly expedited repair and down time.
Aspects of the present invention will enable cost reductions significant enough to make the entire device disposable in nature, being replaced as frequently as every two to five days. A disposable device allows the medication to be prefilled by the manufacturer and does not need the routine cleaning and maintenance required by long term devices, greatly simplifying use for the patient. Similar to disposable cameras which have become increasingly popular in recent years, another benefit is that each time a disposable fluid delivery device is purchased, it is the latest or state of the art technology. Long term use devices may be outdated in a year when a new version is available from the manufacturer, just twenty five percent of the life expectancy of the original device.
The present invention, therefore, provides a device for delivering fluid to a patient, including an exit port assembly adapted to connect to a transcutaneous patient access tool, a dispenser for causing fluid from a reservoir to flow to the exit port assembly, a local processor connected to the dispenser and programmed to cause a flow of fluid to the exit port assembly based on flow instructions from a separate, remote control device, and a wireless receiver connected to the local processor for receiving the flow instructions from a separate, remote control device and delivering the flow instructions to the local processor. The device also includes a housing containing the exit port assembly, the dispenser, the local processor, and the wireless receiver. The housing is free of user input components for providing flow instructions to the local processor in order to reduce the size, complexity and costs of the device, such that the device lends itself to being disposable in nature.
According to one aspect of the present invention, the flow instructions cause a predetermined rate of fluid flow for a predetermined period. According to another aspect, the predetermined rate of fluid flow comprises a basal rate.
According to another aspect of the present invention, the flow instructions cause a predetermined volume of fluid to flow for a predetermined period. According to an additional aspect, the predetermined volume comprises a bolus volume.
According to an additional aspect, the device includes a least one user interface component accessible from an exterior of the housing for causing a predetermined volume of fluid to flow for a predetermined period, independently of the local processor. According to a further aspect, the device includes a least one user interface component accessible from an exterior of the housing for occluding flow to the exit port assembly.
According to another aspect of the present invention, the device includes a power supply connected to the local processor. According to an additional aspect, the device includes a transmitter connected to the local processor for transmitting information from the local controller to a separate, remote control device. According to still a further aspect, the housing is free of user output components for providing information from the local processor. According to a further aspect, the exit port assembly includes a tubular member for transcutaneously entering a patient. According to still a further aspect, the device includes a reservoir.
The present invention also provides a system including a fluid delivery device as described above, and further including a separate, remote control device including a remote processor, user input components connected to the remote processor for allowing a user to provide instructions to the remote controller, and a transmitter connected to the remote controller for transmitting the instructions to the receiver of the fluid delivery device. Thus, the remote controller allows a user, such as a patient, nurse or doctor, to remotely program the fluid delivery device to provide a desired infusion of fluid into the patient.
The present invention further provides another device for delivering fluid to a patient, including an exit port assembly adapted to connect to a transcutaneous patient access tool, a dispenser for causing fluid from a reservoir to flow to the exit port assembly, a local processor connected to the dispenser and programmed to cause fluid flow to the exit port assembly based upon flow instructions. The local processor is also programmed to provide flow information, and a wireless transmitter is connected to the local processor for transmitting the flow information to a separate, remote control device. A housing contains the exit port assembly, the dispenser, the local processor, and the wireless transmitter, and is free of user output components for providing the flow information from the local processor to a user.
These aspects of the invention together with additional features and advantages thereof may best be understood by reference to the following detailed descriptions and examples taken in connection with the accompanying illustrated drawings.